Hunter J P, Ashby P, Lang A E
Playfair Neuroscience Unit, University of Toronto, Toronto Western Hospital, Ontario, Canada.
J Neurol Neurosurg Psychiatry. 1988 Nov;51(11):1405-10. doi: 10.1136/jnnp.51.11.1405.
Reflex pathways to tibialis anterior motoneurons from low threshold afferents of the common peroneal nerve were examined in 13 Parkinsonian subjects and 12 age-matched normals. Post-synaptic events occurring in single motoneurons were derived from changes in the firing probability of single voluntarily activated motor units during afferent stimulation. A period of increased firing probability of "monosynaptic" latency (about 33 ms) occurred in all subjects in both groups. A second, later, period of increased firing probability (latency about 64 ms) was seen in 2/12 normals and 8/13 Parkinsonian subjects. Neither of these responses could be produced by cutaneous stimulation. The electrical threshold of the afferents mediating the later effect was 0.82 of the threshold of alpha motoneuron axons which is similar to that of the afferents mediating the shorter latency response. Thus, large non cutaneous afferents contribute to this long latency response in man presumably through polysynaptic pathways. Transmission in these pathways is enhanced in Parkinson's disease.
在13名帕金森病患者和12名年龄匹配的正常对照者中，研究了来自腓总神经低阈值传入纤维至胫前运动神经元的反射通路。单个运动神经元中发生的突触后事件源自传入刺激期间单个自主激活运动单位放电概率的变化。两组所有受试者均出现“单突触”潜伏期（约33毫秒）放电概率增加的时期。在12名正常对照者中的2名以及13名帕金森病患者中的8名中观察到第二个较晚出现的放电概率增加时期（潜伏期约64毫秒）。这些反应均不能由皮肤刺激产生。介导较晚效应的传入纤维的电阈值为α运动神经元轴突阈值的0.82，这与介导较短潜伏期反应的传入纤维的阈值相似。因此，大型非皮肤传入纤维可能通过多突触通路对人类的这种长潜伏期反应起作用。在帕金森病中，这些通路的传递增强。
